3.1.2 - Amount of Substance

Question 1

How many atoms does one mole of any substance contain?

Answer 1

6.02 x 10^23 atoms/particles

Question 2

What is the value of Avogadro’s Constant?

Answer 2

6.02 x 10^23

Question 3

How do you calculate percentage yield?

Answer 3

(Actual yield/theoretical maximum yield) x 100

Question 4

How do you calculate percentage atom economy?

Answer 4

(Mass of desired product/sum of total masses of all reactants) x 100

Question 5

How do you convert between degrees celsius and kelvin?

Answer 5

+ 273 (0 degrees C = 273K)

Question 6

How do you convert between cm3 and dm3?

Answer 6

/1000

Question 7

How do you convert between Pa and kPa?

Answer 7

x 1000

Question 8

Number of particles = ____ x _____

Answer 8

Number of particles = number of moles x Avogadro’s constant

Question 9

Number of moles = _____ / ______

Answer 9

Number of moles =mass (g) /mass of one mole (g)

Question 10

Mass = Mr x ____

Answer 10

Mass = Mr x moles

Question 11

Moles = concentration x _____ (give units)

Answer 11

Moles = concentration (mol dm^-3) x volume (dm^3)

Question 12

State the ideal gas equation and units

Answer 12

pV = nRT

p: pressure, Pa
V: volume, m3
n: no. of moles
R: gas constant (always given)
T: temperature, K

Question 13

The volume occupied by any gas under standard conditions is what?

Answer 13

24dm^3

Question 14

What are standard conditions?

Answer 14

100kPa, 298K (25 degrees C)

Question 15

What is the ‘molar mass’ of a substance? Units?

Answer 15

The mass per mole of a substance

Units: g mol^-1 (equal to Mr)

Question 16

Define ‘empirical formula’

Answer 16

The simplest whole number ratio of atoms of each element in a compound

Question 17

Define ‘molecular formula’

Answer 17

The actual number of atoms of each element in a compound